Scrub jays (Aphelocoma coerulescens) remember the relative time of caching as well as the location and content of their caches.

Abstract

Two experiments examined whether food-storing scrub jays (Aphelocoma coerulescens) could remember when they cached particular food items as well as what they cached and where. In Experiment 1, scrub jays cached and recovered perishable "wax worms" (wax moth larvae) and nonperishable peanuts in 2 visuospatially distinct and trial-unique trays. The birds searched preferentially for fresh wax worms if they had cached them 4 hr earlier but rapidly learned to search for peanuts and avoid decayed wax worms that had been cached 124 hr previously. This pattern also was observed when the food items were removed before recovery on test trials. These results were replicated in Experiment 2 using a procedure in which both types of food were cached in different sides of the same caching tray: On the basis of a single, trial-unique experience, scrub jays could remember the relative time of caching as well as what type of food was cached in each cache site.

Pigeons learn to answer the question “where did you just peck?” and can report peck location when unexpectedly asked

“…In the animal research cited (Babb & Crystal, 2006;Clayton & Dickinson, 1999a, 1999b, subjects are trained to answer an expected question. Thus, in the case of the scrub jays, the acquired rule might have been "if the memory (trace) of having cached worms is strong, look where you cached the worms, but if the memory of having cached worms is weak, look where you cached the peanuts.…”

Episodic-like memory in pigeons

“…Any task in which training involveswhat could be described as the acquisition of a set of rules cannot preclude semantic-like knowledge of the kind "if vertical then red, if horizontal then green." This is true even when the sample requires memory for "what," "where," and "when" information, such as that reported by Clayton and Dickinson (1999) and by Shimp (1976). Clayton and Dickinson (1999) trained scrub jays to cache, in distinctive locations (where) for later retrieval, more preferred wax worms or less preferred peanuts (what).…”

“…This is true even when the sample requires memory for "what," "where," and "when" information, such as that reported by Clayton and Dickinson (1999) and by Shimp (1976). Clayton and Dickinson (1999) trained scrub jays to cache, in distinctive locations (where) for later retrieval, more preferred wax worms or less preferred peanuts (what). Because the more preferred wax worms went bad within a couple of days, time since caching (when) was manipulated as well.…”

The fine-grained spatial abilities of three seed-caching corvids

“…This was not the case, however ( Figure 3C), suggesting that the differences in the time courses of pecking shown in Figure 3A may be due to differences in temporal judgments rather than motivation. Although temporal factors would appear to play an important role for any animal that caches (Clayton & Dickinson, 1999), the pattern of results suggests that scrub-jays and pinyon jays are relatively poorer than nutcrackers at discriminating temporal relationships (i.e., determining when the FI would terminate). An extensive comparative analysis of the ability of food-storing and nonstoring species to make temporal discriminations has not been conducted, and further empirical work in this domain would be of interest.…”